unit Umd5;

interface

uses  Windows,  SysUtils;

 type
    THash = DWord;
    function md5 (buf: string): string;


implementation

var HEX: array[Word] of string;
function LRot32 (a, b: LongWord): LongWord; 
asm 
  mov  ecx, edx 
  rol  eax, cl 
end; 

function md5 (buf: string): string; 
type 
  pint = ^Integer; 
  tdata = array [0..15] of DWORD; 
  pdata = ^tdata; 
  tbyte = array [0..15] of byte; 
  pbyte = ^tbyte; 
var 
  i, Len: Integer; 
  data: pdata; 
  CurrentHash: array[0..3] of DWord; 
  P: array[0..7] of Word absolute CurrentHash; 
  A, B, C, D: DWord; 
begin 
  Len := Length (buf); 
  SetLength (buf, 64); 
  buf[Len+1] := #$80; 
  FillChar (buf[Len+2], 63 - Len, 0); 
  pint (@buf[57])^ := Len * 8; 

  CurrentHash[0] := $67452301; 
  CurrentHash[1] := $efcdab89; 
  CurrentHash[2] := $98badcfe; 
  CurrentHash[3] := $10325476; 

  A := CurrentHash[0]; 
  B := CurrentHash[1]; 
  C := CurrentHash[2]; 
  D := CurrentHash[3]; 

  data := addr (buf[1]); 

  A := B + LRot32 (A + (D xor (B and (C xor D))) + data^[ 0] + $d76aa478, 7); 
  D := A + LRot32 (D + (C xor (A and (B xor C))) + data^[ 1] + $e8c7b756, 12); 
  C := D + LRot32 (C + (B xor (D and (A xor B))) + data^[ 2] + $242070db, 17); 
  B := C + LRot32 (B + (A xor (C and (D xor A))) + data^[ 3] + $c1bdceee, 22); 
  A := B + LRot32 (A + (D xor (B and (C xor D))) + data^[ 4] + $f57c0faf, 7); 
  D := A + LRot32 (D + (C xor (A and (B xor C))) + data^[ 5] + $4787c62a, 12); 
  C := D + LRot32 (C + (B xor (D and (A xor B))) + data^[ 6] + $a8304613, 17); 
  B := C + LRot32 (B + (A xor (C and (D xor A))) + data^[ 7] + $fd469501, 22); 
  A := B + LRot32 (A + (D xor (B and (C xor D))) + data^[ 8] + $698098d8, 7); 
  D := A + LRot32 (D + (C xor (A and (B xor C))) + data^[ 9] + $8b44f7af, 12); 
  C := D + LRot32 (C + (B xor (D and (A xor B))) + data^[10] + $ffff5bb1, 17); 
  B := C + LRot32 (B + (A xor (C and (D xor A))) + data^[11] + $895cd7be, 22); 
  A := B + LRot32 (A + (D xor (B and (C xor D))) + data^[12] + $6b901122, 7); 
  D := A + LRot32 (D + (C xor (A and (B xor C))) + data^[13] + $fd987193, 12); 
  C := D + LRot32 (C + (B xor (D and (A xor B))) + data^[14] + $a679438e, 17); 
  B := C + LRot32 (B + (A xor (C and (D xor A))) + data^[15] + $49b40821, 22); 

  A := B + LRot32 (A + (C xor (D and (B xor C))) + data^[ 1] + $f61e2562, 5); 
  D := A + LRot32 (D + (B xor (C and (A xor B))) + data^[ 6] + $c040b340, 9); 
  C := D + LRot32 (C + (A xor (B and (D xor A))) + data^[11] + $265e5a51, 14); 
  B := C + LRot32 (B + (D xor (A and (C xor D))) + data^[ 0] + $e9b6c7aa, 20); 
  A := B + LRot32 (A + (C xor (D and (B xor C))) + data^[ 5] + $d62f105d, 5); 
  D := A + LRot32 (D + (B xor (C and (A xor B))) + data^[10] + $02441453, 9); 
  C := D + LRot32 (C + (A xor (B and (D xor A))) + data^[15] + $d8a1e681, 14); 
  B := C + LRot32 (B + (D xor (A and (C xor D))) + data^[ 4] + $e7d3fbc8, 20); 
  A := B + LRot32 (A + (C xor (D and (B xor C))) + data^[ 9] + $21e1cde6, 5); 
  D := A + LRot32 (D + (B xor (C and (A xor B))) + data^[14] + $c33707d6, 9); 
  C := D + LRot32 (C + (A xor (B and (D xor A))) + data^[ 3] + $f4d50d87, 14); 
  B := C + LRot32 (B + (D xor (A and (C xor D))) + data^[ 8] + $455a14ed, 20); 
  A := B + LRot32 (A + (C xor (D and (B xor C))) + data^[13] + $a9e3e905, 5); 
  D := A + LRot32 (D + (B xor (C and (A xor B))) + data^[ 2] + $fcefa3f8, 9); 
  C := D + LRot32 (C + (A xor (B and (D xor A))) + data^[ 7] + $676f02d9, 14); 
  B := C + LRot32 (B + (D xor (A and (C xor D))) + data^[12] + $8d2a4c8a, 20); 

  A := B + LRot32 (A + (B xor C xor D) + data^[ 5] + $fffa3942, 4); 
  D := A + LRot32 (D + (A xor B xor C) + data^[ 8] + $8771f681, 11); 
  C := D + LRot32 (C + (D xor A xor B) + data^[11] + $6d9d6122, 16); 
  B := C + LRot32 (B + (C xor D xor A) + data^[14] + $fde5380c, 23); 
  A := B + LRot32 (A + (B xor C xor D) + data^[ 1] + $a4beea44, 4); 
  D := A + LRot32 (D + (A xor B xor C) + data^[ 4] + $4bdecfa9, 11); 
  C := D + LRot32 (C + (D xor A xor B) + data^[ 7] + $f6bb4b60, 16); 
  B := C + LRot32 (B + (C xor D xor A) + data^[10] + $bebfbc70, 23); 
  A := B + LRot32 (A + (B xor C xor D) + data^[13] + $289b7ec6, 4); 
  D := A + LRot32 (D + (A xor B xor C) + data^[ 0] + $eaa127fa, 11); 
  C := D + LRot32 (C + (D xor A xor B) + data^[ 3] + $d4ef3085, 16); 
  B := C + LRot32 (B + (C xor D xor A) + data^[ 6] + $04881d05, 23); 
  A := B + LRot32 (A + (B xor C xor D) + data^[ 9] + $d9d4d039, 4); 
  D := A + LRot32 (D + (A xor B xor C) + data^[12] + $e6db99e5, 11); 
  C := D + LRot32 (C + (D xor A xor B) + data^[15] + $1fa27cf8, 16); 
  B := C + LRot32 (B + (C xor D xor A) + data^[ 2] + $c4ac5665, 23); 

  A := B + LRot32 (A + (C xor (B or (not D))) + data^[ 0] + $f4292244, 6); 
  D := A + LRot32 (D + (B xor (A or (not C))) + data^[ 7] + $432aff97, 10); 
  C := D + LRot32 (C + (A xor (D or (not B))) + data^[14] + $ab9423a7, 15); 
  B := C + LRot32 (B + (D xor (C or (not A))) + data^[ 5] + $fc93a039, 21); 
  A := B + LRot32 (A + (C xor (B or (not D))) + data^[12] + $655b59c3, 6); 
  D := A + LRot32 (D + (B xor (A or (not C))) + data^[ 3] + $8f0ccc92, 10); 
  C := D + LRot32 (C + (A xor (D or (not B))) + data^[10] + $ffeff47d, 15); 
  B := C + LRot32 (B + (D xor (C or (not A))) + data^[ 1] + $85845dd1, 21); 
  A := B + LRot32 (A + (C xor (B or (not D))) + data^[ 8] + $6fa87e4f, 6); 
  D := A + LRot32 (D + (B xor (A or (not C))) + data^[15] + $fe2ce6e0, 10); 
  C := D + LRot32 (C + (A xor (D or (not B))) + data^[ 6] + $a3014314, 15); 
  B := C + LRot32 (B + (D xor (C or (not A))) + data^[13] + $4e0811a1, 21); 
  A := B + LRot32 (A + (C xor (B or (not D))) + data^[ 4] + $f7537e82, 6); 
  D := A + LRot32 (D + (B xor (A or (not C))) + data^[11] + $bd3af235, 10); 
  C := D + LRot32 (C + (A xor (D or (not B))) + data^[ 2] + $2ad7d2bb, 15); 
  B := C + LRot32 (B + (D xor (C or (not A))) + data^[ 9] + $eb86d391, 21); 

  Inc (CurrentHash[0], A); 
  Inc (CurrentHash[1], B); 
  Inc (CurrentHash[2], C); 
  Inc (CurrentHash[3], D); 

  Result := StrLower(PChar(HEX[P[0]]));
  for i := 1 to 7 do 
  Result := Concat (Result, StrLower(PChar(HEX[P[i]])));

end;

var DEC, Tmp: Integer;
    LH: string;

initialization

for DEC := 0 to $ffff do 
begin
  Tmp := DEC and $ff; 
  LH := IntToHex (Tmp, 2);
  Tmp := DEC shr 8;
  HEX[DEC] := Concat (LH, IntToHex (Tmp, 2)); 
end;
end.
